[cobrashoch]

greenwater- This is a very old question that comes up from time to time. I could only answer it with another question. What are you trying to do with your car? That alone will dictate the direction you will have to go in. Along the way though a few things can be added both pro and con though.
First, the costs of supercharging will approach the 3800$ by the time you get it set up right unless you can find a price reduced air pump in the first place. You will have to come up with a pressure box and a popoff valve to protect your engine to. Also true that a supercharger will create a whole plathoria of problems that will need to be addressed, i.e.- overheating,pre-ignition control,component strength problems , drive train issues and others. All of this stuff can be tempered by your driving skills. Sounds confusing doesn't it? That's why I always tell anyone going this way the first time to find someone with a track record here to lean on. For the non B.S. crowd this is the only way to go though if the rules permitt it.
Second the cost of the webber setup is pert-near the 4000$ if you can set them up yourself only. True they can be tuned to give instant engine response and another thing they wil do is end fuel starvation problems when going around turns fast. As for being a power adder though, todays electronic fuel injection will match the performance levels of a webber setup. Also carbs with mid range tuning (to replace power valves) will get you close with tuning.
Both systems have the " WOW " factor when you pop the hood with the supercharger appealing to the hot rod crowd and the webbers apting to the purests and the sports car crowd.
Paxtons have been around since the early 60's though somewhere in there they came from the old McCallic (sp) superchargers. Today Paxton and Vortec superchargers are both owned by the same company I am told. Lots of luck on you quest. cobrashoch